Hot melt adhesive material extruders or dispensers, often referred to as "glue guns" within the industry have provided an improved system for applying heated adhesive materials or the like. While the individual structures used by manufacturers to provide effective hot melt material dispensers have been subject to substantial variation, all generally include a housing supporting a heating chamber. The heating chamber defines an internal melt passage. An electrical power source such as a resistance heating element is thermally operative upon the heating chamber to provide elevated temperature within the melt passage. An elongated rod or bar of meltable adhesive material or the like is introduced into the heating chamber melting passage and partially or completely liquified therein and is discharged outwardly from the heating chamber through a dispensing nozzle.
For example, U.S. Pat. 4,463,877 issued to Siwon sets forth a DEVICE FOR GUIDING A ROD-SHAPED MEMBER FORMED OF A GLUING MATERIAL WHICH CAN BE SOFTENED BY HEAT in which a heater supports a flexible cartridge secured to one end thereof by a metal sleeve. The metal sleeve extends beyond the heater and surrounds a portion of the cartridge for conducting heat to a section of the cartridge removed from the heater. In one embodiment, the metal heat conducting sleeve is formed of a pair of coiled metal wires.
U.S. Pat. No. 5,026,187 issued to Belanger, et al. sets forth a DISPENSER FOR HOT-MELT MATERIAL which includes a heat conductive removable cartridge containing the to-be-melted adhesive together with a chamber for receiving the cartridge and a heater adjacent the cartridge for melting the adhesive prior to dispensing through the nozzle. Pressure is applied through a plunger coupled to the material to expel adhesive through the nozzle.
U.S. Pat. No. 4,949,881 issued to Watanabe, et al. sets forth a PORTABLE GUN-TYPE ADHESIVE DISCHARGER having a material dispensing nozzle and a chambered heating element supported within a pistol grip housing A removable plunger is received within the pistol grip housing and slidably movable to exert pressure against the heated material. A pistol grip level is pivotally coupled to the housing and is squeezed by the user. The interior end of the lever is operatively coupled to the movable plunger to exert a force used to feed the adhesive stick toward the heating chamber.
U.S. Pat. No. 4,948,944 issued to Oster sets forth a COMPACT HEATER ASSEMBLY FOR A HOT MELT APPLICATOR having a pistol grip-shaped housing supporting a heating chamber and dispensing nozzle therein. A movable lever is coupled to a material feeding mechanism which is operative as the handle is squeezed to feed material into the melting chamber.
U.S. Pat. No. 4,938,388 issued to Yeh sets forth a GLUE TRANSPORT MECHANISM FOR A MOLTEN GLUE DISCHARGING DEVICE having a heating element, a transporting tube and a gear to move the introduced glue strips such that the melted glue is delivered through a tube.
U.S. Pat. No. 4,916,289 issued to Suhanek sets forth a PLASTIC WELDER having a pistol grip housing supporting a heating element and a supply rod of meltable material supportable therein. A feeding mechanism operates automatically to provide movement of the melt material into the heating element.
U.S. Pat. No. 4,826,049 issued to Speer sets forth a CORDLESS ADHESIVE DISPENSING SYSTEM having an electrically heated dispensing gun and cooperating base for supporting the gun. Mechanical and electrical connections are provided between the base and the gun.
U.S. Pat. No. 4,815,636 issued to Stede, et al. sets forth a HOT MELT GUN having a melt chamber and a mechanism for feeding a rod of hot melt material into the chamber for melting and dispensing. The feeding mechanism includes a carriage mounted for movement to and from the melt body. A clamp member pivotally mounted on the carriage and a trigger to cause the clamp member to grip the rod and feed it into the chamber as the trigger is moved.
U.S. Pat. No. 4 795 064 issued to Shew sets forth a GAS HEATED GLUE GUN having a heating chamber and a self-contained supply of gas and a burner mechanism for heating the melt material within the heating chamber.
U.S. Pat. No. 4,773,566 issued to Hoagland sets forth a HOT MELT ADHESIVE APPLICATOR configured to dispense relatively large volumes of molten adhesive at relatively fast rates. A barrel and rotary valve block are supported within a housing and control the flow of molten adhesive. Heaters attached to the barrel maintain the adhesive in a molten state.
U.S. Pat. No. 4,744,688 issued to Silber sets forth a HAND TOOL FOR APPLYING HOT MELT ADHESIVE includes a housing supporting an applicator roller which receives liquified adhesive through an adjacent slot in a retention chamber.
U.S. Pat. No. 4,014464 issued to Newton, et al. sets forth a HOT MELT DISPENSER AND METHOD OF MAKING ITS MELT BODY in which the melt body is a generally conical melting chamber extending between an inlet and a relatively smaller outlet passage. One or more bypass members are interconnected to the melting chamber by a plurality of spaced radial bores arranged to conduct hot melt from successive outer layers of the material as it is being progressively softened and liquified in the chamber for flowing to the outlet.
U.S. Pat. No. 3,868,046 issued to Maddalena sets forth an EXTRUDER for dispensing highly viscous sealant compounds. The extruder provides a rotatably mounted extruding screw axially mounted within a barrel and a power head for driving the extruding screw to transport the material to an exit orifice in the barrel.
U.S. Pat. No. 3,776,426 issued to Newton sets forth ADHESIVE EXTRUDERS for melting and dispensing heat softenable thermal plastic material such as adhesives. The extruder includes a main body portion having therein a melting chamber, an inlet passageway leading into one end of the chamber and a discharge passageway in communication with the chamber at the other end thereof. The melt chamber defines a cross section which progressively diminishes from the inlet end toward the discharge end.
U.S. Pat. No. 3,543,968 issued to Reighard sets forth a GUN FOR DISPENSING THERMOPLASTIC MATERIALS having a gun-shaped housing and defining a barrel and trigger control mechanism. The gun further defines conduits within the housing and handle which receive thermoplastic material for transport to the heating chamber within the gun-shaped housing.
U.S. Pat. No. 3,459,335 issued to Cohen, et al. sets forth a MANUAL DISPENSER FOR HEATED ADHESIVE in which an elongated cylindrical member defines an interior heating chamber receiving the adhesive or glue. The heating chamber is rigid or shape sustaining and a gas pressure is applied to one end of the melt chamber to cause the fillable adhesive to be dispensed through an outlet in the other end of the chamber.
U.S. Pat. No. 3,298,572 issued to Newton sets forth CEMENT DISPENSERS having a heating chamber defining a dispensing nozzle at one end and an input passage at the other end. A resilient sleeve is secured to the input end of the heating chamber and resiliently supports a rod of to-be-melted adhesive material. U.S. Pat. No. 2,556,609 and 2,681,685 both issued to Arkless and both entitled PLASTIC WELDING DEVICE set forth similar hot melt apparatus having means for dispensing a heated plastic adhesive material which includes a pistol grip housing having a pivotally supported feed lever secured to the handle portion thereof and operatively coupled to the to-be-melted adhesive.
U.S. Pat. No. 3,204,826 issued to Paulsen sets forth a PORTABLE THERMOPLASTIC CEMENT DISPENSERS having a melting chamber securable to the output end of a convention soldering iron. The melting chamber receives an elongated cylindrical rod of to-be-melted material at one end and dispenses melted material out the nozzle supported at the remaining end. The user's finger pressure is applied to the rod of material to force it into and through the heating chamber.
U.S. Pat. No. 3,281,576 issued to Cooper, et al. sets forth an ELECTRICALLY HEATED THERMOPLASTIC CEMENT EXTRUDER having a pistol grip housing supporting an electrically heated melt chamber and receiving an elongated meltable rod of thermoplastic cement. A thumb wheel feed mechanism is rotated to provide a driving force against the thermoplastic cement.
While the foregoing described prior art devices have provided satisfactory operation in many environments, they do not provide a convenient battery-powered structure usable in a low temperature melt child safe environment. There remains, therefore, a need in the art for a low temperature melt child safe battery-powered dispenser for hot melt material.